UNEXPLAINED UPGRADE WITH A SURPRISE DEBIT ORDER

I received a message that I was due for a upgrade. I visited the store in the east rand. I was told it would be due in May 2022 but I could do it in March and get the cellphone as deductions will take place for the new phone in May. Then today 23/03/2022 I get debited three times the amount and when I went to the store to see the manager I they could say is sorry. This is totally unacceptable. I have other financial commitments too - I'm very disappointed