A CALL CENTER that cant get it right to CALL (its a joke)

Ive had 2 debit orders come from my account with 2 reference numbers. Ive tried their chat option online but reply about an hour later and by the time the message comes through, Im already doing something else. They keep asking my contact number or they send me an email to let me know my queries been passed to the relevant department. This has been going round in circles for the fourth day today. Then they say that someone tried calling me today and they're going to give me an old number they dialed. The number I'm using, I got from them on contract, I'll bet anyone my lucky socks thats not the number they dialed. This is a joke. This is a call center, but they cant perform what is their main function........ "CALL" I want to prevent it from happening the next debit order date, Its school fees, school clothes and stationary months, I dont need another additional payment coming from my account. But this "CALL CENTER" dont know how to CALL their clients