Pharmacy recommendation

Looming for some advice folks.

I ordered x3 5mg pens last year from DAM pharmacy. They eventually sent me a 5mg, 7.5mg and 10mg pens over a period of about 4 months. I told them they were available to collect as obviously sent in error and of course they didn’t collect them. I didn’t take them due to an unexpected life event, and about 3 months later they sent me the original x3 5mg pens I ordered, plus 1 more for my inconvenience! This left me with a lot of pens! I started taking them again and have about 2 jabs of the 10mg left.

I want to stay on ithe 10 or go up to 12.5 but I’m guessing I will struggle getting this as have only had a prescription for 5mg. Has anyone experienced something similar who could recommend what pharmacy I should approach to get the higher strength? Or if anyone just knows what pharmacy I should go to that would be great. Cheers