[Jail_Bird]

How many photos are the best to send?

Send one at a time and keep doing so In different file formats with every request.

Assure them that they're working fine on your end, and that you can't understand why they cannot simply open them.

Awesome. I'm working on it right now, hopefully, they will reply quickly, it's been said they will answer in 3-5 working days which is a shame if it's really going to take that long to chat with them.