SHOPPERS who use on the internet and catalogue company Studio are now being urged to check their statements as some say they've been hit with new rates of interest of up 54.5 percent.
Thousands of people have commented on the Facebook post concerning the increases, often claiming they weren't even told about about the changes in advance.
Michelle Lye, who wrote the initial warning on the Extreme Couponing and Bargains UK Facebook group, told The sun's rays she's used the catalogue for a long time with an interest rate close to 29 percent.
But she says she was shocked when she received instructions just before Christmas saying her rate of interest was increasing to 49.9 percent.
And the 42-year-old housewife from Kent says her daughter and pa, who also have Studio catalogue accounts, have experienced their rates upped without any notice whatsoever.
She said: "I always pay by balance promptly and I've only incurred a little bit of interest through the years but Studio sent me a letter saying they were reviewing my account and putting up the eye.
"There was no logic behind why and they couldn't really explain it after i spoke to them on the phone either.
"My daughter and pa have an account too however they didn't get a letter.
"It's disgusting. It is hard for people to go out and buy things upfront, so lots of people depend on this plus they won't notice or perhaps be in a position to afford the interest hike.
"It's putting individuals debt, which in turn causes serious stress. I'm lucky that my account only had around lb40 to lb50 on it and so i could pay it off and shut it."
Michelle's post has since received over 3,700 comments, many from worried shoppers.
One person wrote: "Appreciate sharing, I just looked and mine went up too (didn't even know)!!! I only have a few more payments left and when I'm done I'm closing my account."
Another said: "I checked mine, fuming is not the word, mine's 54.5 percent."
Someone else added: "Just checked my statement… 49.9 percent… I had been never notified. Once my account is paid I won't be utilising them again. Thanks Michelle."
Another grateful shopper wrote: "Appreciate the heads up, I'll be paying down my bill ASAP!!".
Studio wouldn't tell The Sun the number of shoppers may take a hit, what rates happen to be hiked to and from or once the change came into force.
It only asserted the move was due to changes to customers' credit profiles and market conditions.
Under the town watchdog's rules, credit information mill permitted to increase rates on charge cards and retail credit agreements should they have a legitimate reason behind doing this.
This could include increased costs to lend in the first place or perhaps a switch to the customer's circumstances.
But where they do this, firms have to give customers 60 days' notice of any hike, where unhappy users can cancel and shut their account.
If there are debts in your account, firms have to permit you to pay it off at the old rate over a "reasonable period" – although there's no set meaning of what this means in reality.
Unhappy shoppers should first complain to Studio about any rate hike and then try to arrived at an agreement over repayments.
If you don't get the response you would like or don't hear back within 8 weeks you are able to take your complain to the free Financial Ombudsman Service.
A spokesperson for Studio said: “At Studio we take changes to customers' rates of interest very seriously.
"Like a Financial Conduct Authority regulated lender we always communicate any changes and the effective date, prior to this happening.
"We occasionally review rates of interest according to changes to customer credit profile and changing market conditions.”
The move by Studio may come as many of the big banks have announced they're upping rates of interest on overdrafts this April.
If you're struggling, here's how to get out of debt in eight simple steps – and obtain advice free of charge.
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