Anxious about joining and BGV

My joining date for EY GDS is 23 september. I submitted my documents for background verification on 24 july. I haven't got any communication from them regarding confirmation. HR doesn't pick up my call. But, I mailed them to prepone my joining and they responded to that and shifted it to 23 september.

I called HR a few times to seek confirmation of background verification but she didn't respond.

I feel really anxious that they might ghost me even after providing the offer.

Has somebody experienced this?