myMTN NG App

On 27th March 2023, I bought a calling card of #1,000 through my Bank account on myMTN NG app.
I was debited by my Bank (Polaris Bank) but I was not credited.

The same thing happened on 28th April, 2023 when I bought a calling card of #1,000 with the same process and I was debited by my Bank but not credited my MTN line.

So, I want to know if the fault is from my bank or MTN itself