700 test for 6 weeks before any AI? That is probably all the fat gain you think you have as water and general puffiness.
If you have a real 700 test you should be seeing something even if you ate at mcdonalds every day and only moderately worked out. You would add lots of fat that way but you would still see some muscle gain just buried under fat.
Best guess is bad test. I know you said you got it at a pharmacy...but if I had a nickel for every time someone told me that and they had gotten it from where their friend said too instead...
Check your BP if it didn't go up on 700 a week of test I would say the next step is a lab test as something is clearly not working right.
You do realize 700 a week of test is a 100mg/ml bottle every 1.5 weeks or a 200mg/ml bottle about every 3 weeks. Meaning you would have gone through a couple vials by now. Where do you live that you can get several vials from the pharmacy at the same time without the police coming to your door? Even if I had 3 legit prescriptions from 3 diff doctors filled at 3 diff pharmacies I would still have the police if I filled them all in the same month as 1 vial is 4-6 months worth of TRT.