I did post in Style & Beauty yesterday but didn't get an answer, so shamelessly copying & reposting in here for traffic as my appointment is tomorrow and I'd really like to go in better informed! 
Have NC because I think my hairdresser may be on here!
I have very curly, frizzy, fluffy hair. I can tame it, but it takes a lot of work and I'm lazy. I've had Kerastraight several times before and it's okay, but since it's a relaxer rather than a straightener, it really doesn't last long and it's expensive. Last time I had it done, my hairdresser talked about Wella Straight. So I went to book it as I have a special occasion coming up. She wasn't available so booked with another, recommended, stylist there. They then rang with just a few days until my appointment to say because I had highlights (half head, last December) they didn't really want to do it as they were sure it would ruin my hair. It felt more like they were making excuses and maybe just couldn't be bothered as they kept changing their reply every time I challenged something.
Long story short, I spoke to my stylist over the phone and went in for a strand test with her. She then rang back later to say the strand test hadn't damaged my hair, but that it hadn't taken and therefore wouldn't work...
Does anyone know if this is even possible? I had a perm when I was a lot younger, 30-odd years ago, and that took. Why wouldn't it go straight?! It's the same principal as far as it was originally explained to me, just straightening rather than curling.
I really like my own stylist, and up to this point trusted her totally, but not sure about the one I was supposed to be seeing instead, so I guess I'm asking if they are having me on and for whatever reason don't have the time / product / experience / botherance, or could it be that the strand test proved my hair wouldn't straighten?
I'll be really disappointed if my stylist is making excuses for her colleague and to be honest, really hoping someone with experience can back her up!
Thanks very much!