I would say get an appointment with your uro before any more "exercises". Now.
You don't need to have pain to be concerned. If something changes significantly, there is room for concern. The manufacturer's rep is probably not a physician, and not qualified to talk about problems like you describe. If he did, he could be setting himself up for liability issues down the road.
I have been using a pump for two years as rehab (no rings, not for sex, that's where trimix comes in), and have never seen any such deformation.
Moderator - Prostate Cancer(Not a medical professional)
My adjuvant IGRT journey (2010) - www.healingwell.com/community/default.aspx?f=35&m=1756808
HT (Lupron) 6-mo injection 9/12;Prolia 6-mo inj 12/12