Does anyone know of a supermarket in Benidorm that sells PROVAMEL ricemilk??

In Benidorm I haven't seen it, but in La Nucia there is a big international supermarket that sells lots of stuff from the UK and the rest of Europe, chances are you'll get it there. In Alfaz de Pi there is a Quik Save British supermarket but again I can't recall seeing it, as usually they only stock things that the majority of people use.
Another idea is that you try in any health food store they sell soya milk, goats milk and probably ricemilk but may not sell your brand.

I'm not sure about this, but I should think your best bet would be to take the bus (no.12) up to Carrefour in Centro Commercial La Marina. It is by far the biggest and most comprehensive Supermarket in the area.
If I see it on my travels I will be sure to let you know.

I shop in Carrefour each week and haven't seen this. However, they do have all types of milk eg soya. You might get it in their section for diabetics and dieters. If not ask in a chemist and they should be able to tell you. Or what about the manufacturers themselves. It's worth an e mail to them to ask where you can buy it in Spain.

My cousin, who lives there , will let me know this week where you can buy it and I will let you know.His son makes his money by coming over to the uk once a month and stocking up his van with British goods which he sells to the local shops for 'discerning'people like us.
Although, La Nucia is about 8 miles away, the supermarket mentioned earlier is particularly good - so is Benidorm market.