A referral veterinary surgeon will want paying for treatment. But the PDSA may not pay for the treatment, please search on the internet and ask there advice about it, some local charites will sometimes help pay such as the RSPCA, dogs trust etc.. but you have to approach them and ask. It may mean that you have to continue at the PDSA as this is free treatment but please chat with the veterinary surgeon seeing Bremmer and state that you are not happy with the treatment and ask them to be more invasive with the investigations as its being left unresolved. Or see a different surgeon at the PDSA as a second opinion. Again sorry i can not be of more help but referral veterinary medics are very expensive. But they are excellent at there jobs. Good luck .