I have a towel rail that has just fallen off of its bracket, the one it fell off of has crumbled and I can’t find one anywhere online. The brand of towel rail is Phoenix. This image is the one that is in tact still.
Tradelink and Reece seem to be the main suppliers.
Website doesn't mention spare parts but you may find your model there and it wouldn't hurt to ask them.
It's great that you've received fantastic advice from @Brad. Just to add to his recommendation, if you find that you are not able to find a mounting block for your shower rail, you can try to replicate it using a Metal Mate 10 x 10 x 1.5mm 1m Aluminium Channel. I recommend using a Metal File to trim it into shape. You can also adjust the height of the bracket by cutting the bottom end off to form a double "L" configuration facing each other.
If you need more advice or information, please let us know.
Unless tradelink or Reece have open packets or loose parts floating around I very much doubt you can get replacement parts and to make a replacement part? how long will it last. the best solution is to replace the complete unit. My next question is how old is its rail?