Teljoy put intrest rate on during lockdown and dont want to assist with payment of acc.

Ive tried contacting teljoy regatding my paymemts on my acc. For the past 2 years ive paid my acc no late payment nothing. For the month of april i didnt get any orders in and my husband passed away in jan'20. My acc is up to date. But because all orders etc has been canselled for the mont of april i do not have the funds to pay at the end of april. Im self enployed and run my bisness from my home. My bisness is not a reg bisness as from the beginning. I cant get hold on the contact nr provided on the net. Ive sent alot of emails but nothing. But teljoy could sent me a message stating that im going to pay 7% more interest on my acc from the 1st of May'20. When the repo rate goes down teljoy uped it by 7%. I need to arrange payment on my acc because i will not have the funds to pay end of april. And please explaine the 7% increase aswell. Thanks