Double debited in December for no reason

I’m debited twice for December in my RCP account, no one was saying anything about until I called & was told there’s a technical error & monies will be reversed but until now no monies has been reversed. Why technical error is only in December & on Christmas time? Who does that to clients during Christmas time when they have to look after their families? Strange enough with this pathetic bank, If you miss one payment with them they handover your account strait away being their client for years but it’s ok for them to double debit your account without even contacting you to inform & apologise.