The pharmacy here in Sweden sells it over the counter, so it should be over the counter everywhere (virtually EVERYthing needs a prescription here, and if Voltaren Gel doesn't, then it should be available everywhere).
Google Voltaren Gel and see if you can find it at an online pharmacy, if you can't find it near you.
You might even try MSM powder, dissolved in oil or aloe vera gel, and massaged in. Jarrow has a good quality product (many are not good - especially those from China). I get mine online from iherb.com - good quality at good prices.
You need a prescription for it. My rheumy prescribed it for me and I love it!