Wrongly debited

I have a contract with telkom last year Dec they didn't debit then I went to the shop and ask for a statement so that I can pay my account cash which I did and now they debited R888 this morning after the R545 that I've paid on the 25 last week and it's not the first time they don't refund my money yet the account is not going down or anything I want my R888 refund back as I've already paid R545 for January I'm sick and tired of the way they debit on my account I'm okay with paying my account at pep cash they can see mos on their system within 48hrs that I've already paid