Someone put r134a in my r22 system. What do I do?

They had to know, since the valve to add the coolant is different. Did they drain all of the old out and do a complete conversion ?

There is no such thing as a conversion from r22 to r134a on a residential ac system, only on vehicles. I don't know what to tell you, as I have never heard of anyone doing this. Just hope it didn't ruin your equiptment. I would suggest contacting a professional heating and cooling company and see if they won't reclaim the 134, and recharge with 22. R22 is still available, little more pricey than it used to be, but its out there, and still legal to use. I would suggest getting my money back, and possibly requiring them to pay to replace the complete system. Whoever did this is not licensed in refrigeration and should not be allowed to work in the field (in my opinion.)