Rip off! Do not recommend to anyone

I spoke with the Assistant Manager about some discrepancies. I explained to her that there was discrepancies in the amounts I paid for products. I returned an unopened sunscreen worth £28 pounds, and was told I only had £27 pounds in my account.
I had another consultation, and was told that £20 pounds of that amount only was refundable - later one therapist says that the consultation fees is £20, the other says £25. I should have been able to receive at least £25, but was never given the option.
In an effort to get my money back, I bought an Obagi Vitamin C serum 10%. I paid close to £60 pounds for this product. I was told I received 10% off as a special courtesy extended to me. However, when I called as an anonymous customer, the receptionist automatically deducted 10% when informing me of the price. I asked to speak to an manager right away (while on the phone), but was told I would be called back. I never was.
Furthermore, I never receive a receipt informing me of my purchases. The only receipt I ever receive is straight from the card machine, telling me only of the total. Given all these discrepancies, I felt there was a loss of trust between the company and myself. Destination Skin has good treatments, but I was being ripped off. I asked the Assistant Manager for a full refund on my Obagi product as an apology for their mishaps, and as a way to mend broken trust.
She was incredibly rude, talked over me, insinuated I had an ulterior motive and insisted I make my intentions clear. When I tried to speak, she said loudly, ‘You aren’t listening to me’. As a customer paying hundreds of pounds to the company, this is not how I expect to be treated. She informed me that she would see about the refund and give me a call.
She never gave me a call - this was the second time that my concerns were completely ignored. When I came in two weeks later for my fourth and final peel session, the receptionist was oddly cold and I felt the staff was walking on eggshells around me. I was made to feel embarrassed for even mentioning the fact that I disagreed with their payment policies.
As I was sitting there, I watched another customer who paid, who stated, ‘Wait - I thought my treatment was cheaper?’. She paid and was given the same receipt I was - the one from the cardholder and not an official receipt of purchases.