PLEASE HELP! Today I had a Decelor facial and mage, then I used ST Tropez tan and have come out in a rash!!?

I am so shocked. I went for my first ever facial today, was so excited and the lady gave me a really nice back and neck mage with a decelor 'balm' which she commented was 97% natural. I got home feeling refreshed and great. About an hour ago I applied St tropez (which i use all the time) all over my body, and within seconds my skin was burning. It felt like it was on fire or was going to melt, I was so shocked i ran to the shower and had an icy cold shower washing all the st tropez off. the result was a huge, burning red rash (and i mean beetroot red) that felt like VERY bad sunburn all over the ares where she applied the balm! The rest of my body was unnafected. So please can anyone shed any light on this? Which product was to blame and can anyone pinpoint the chemical that might have caused the reaction? St tropez is expensive and I've wasted tons of it, not to mention the pain im in!! Anyone experienced this?? (sorry for the essay)