What a mess - Black limestone and acid!!!

[Not an expert]

I know - I've been a complete idiot according to this site. I've read and read advice and now just need to know what to do to rectify the slabs. I had a patio laid by someone recommended (it is his business so not a layman). Anyway once laid, lots of cement deposit on it. Was given a bottle of acid told to mix it 50/50 and the cement would disappear. Well you know the rest. I had some patio sealant which I've applied to see if it would improve it (Wickes own brand) which has lifted the colour tremendously but still the acid treated bits are showing through. I see that pressure washing may leave marks and I tried a small patch with some steel wool (very lightly) that didn't work. So - is there such a thing as a black stain that I can add to the sealant to cover-up the mess? Help please. You don't want to know how much this has cost me and I'd saved up to get it done so there isn't a huge deal of cash to rectify this

[RAPressureWashing]

Unfortunately not a lot you can do with this other then strip the Wickes sealer off first, then the paving is going to need to be re-cleaned and re-honed to balance the acid etch marks you have as the face of the stone has been damaged then resealed using a proper colour enhancing impregnating sealer.
What idiot gave you (and it sounds like brick acid) an acid that you just mix 50/50 did they know what they were giving you seeing as you have Limestone?

[PavingSuperstore]

If it's just a few slabs, you may be able to remove just these ones and replace them, but I'm guessing you've probably used it all over?