If it makes any difference m8 i got upgraded from 50 to 100 over the phone.i already had a hub after it was swapped out when i was on 50..
I think it depends on who you get when you call.some seam to be better informed than others. as someone else said you could be showing high/low power levels and they could be needing adjusted ,but they should have told you that and anyway adjusting power levels should not be a chargeable call out..
call retentions