I mistakenly borrowed airtime on my MTN line how can I reverse it

i mistakenly borrowed airtime worth 5,000 from mtn and i want it reversed please

I mistakenly borrowed 5,000 this morning from MTN and I really want it reversed please

My previous data expired, so i need data to buy airtime. I wanted to borrow the smallest plan to use my bank app. But i mistakenly borrowed 920 for 1gb(valid for 7 days)