Overcharging on Account

Edgars unilaterally changed my account of almost 20 years, from a 6 month no-interest account to an interest bearing account, without advising me nor getting my permission to do so. Due to this I have not used the account other than for the Club Membership. Since August 2022, Edgars has started charging interest on my account, even though it is paid in full before the 1st of every month. I have tried for four months to get them to correct and reverse this, and every month they just keep charging interest on top of the interest. I haven't been able to get past their customer care to speak to someone in the accounts department to make the amendments. It is very frustrating and I would not recommend that anyone open an account with this company.