My friend has BUPA insurance and he had an MRI scan, a template biopsy and a consultation with a specialist privately, within I think, around three weeks.
If you are so worried about it, and will be fretting for weeks, see if you can get a quicker mpMRI somewhere else. Try and find a scanner with 3T (the best) resolution. If you have to drive a few miles for a one hour procedure, surely it’s worth it to save weeks of worry.
Your insurance company will know more about it and which hospitals they have contracts with. Tell them you find the the wait unacceptable. I had my MRI much quicker than that on the NHS.