Pre-filled syringes- bad?

Just picked up my month’s supply of T from my clinic. For this refill, they gave me a month’s worth of injections in pre-filled syringes. When I asked they said they can’t dispense vials of medication (not sure why). I was under the impression that you shouldn’t leave testosterone in syringes for more than about a week. How risky is a month? Will the testosterone lose potency? Also, would it be dumb to inject syringes into my previous vial so the T isn’t sitting in plastic and rubber syringes? Thanks.