Very poor customer service

Great greek dentist, nice modern facilities but management ineffective and unprofessional. After receiving incorrect advice regarding home tooth whitening I had discolouration and swelling of my gums and no improvement in the colour. Following discussion with 'management' (in inverted commas as no one introduced themselves so I wasnt quite sure who anyone was), it was suggested I could pay (at cost price) for more bleach (even though it was because of the lack of/incorrect advice that the treatment hadnt worked). While I was reading the info re to tooth whitening (I had suggested it might be a good idea for patients to be given written info), a member of staff produced some expired vials of bleach from her handbag which she said were good for a year. However, afterwards when I'd had time to reflect, I was not satisfied with how my complaint had been handled and so wrote to the practice. It took 6 weeks to get a resolution and that was only after several phone calls from myself re the lack of response. I was constantly fobbed off, being told the manager was on holiday or was bereaved. I couldnt understand why no one else could deal with my complaint in her absence. Unsurprisingly, I left the practice very soon after which was unfortunate as the dentist was excellent.
ps I'm still waiting on a reply to my letter of complaint to the owner of the practice and that was last year!