I'm telling you, the cost of ordering every reinker I needed was gagging. But I made it into my Christmas present to myself. And I really use my Distress Inks constantly, so I need to have the reinkers.
I feel for you Shaz, and others outside the USA who have to struggle to get supplies. I don't own any other Ranger inks - other than Distress, I use SU, Colorbox Fluid Chalk, Versafine and Memento.
Sadly, you may just have to accept the solution of buying new pads when yours run dry. If they are available easily in the UK, it seems much cheaper than trying to get the reinkers when you factor everything in. Although if you regularly order or buy from one vendor or another, I would make a complaint. If they sell the pads, they should sell the reinkers.