It sounds like you spent $70 for a $10 result
, what i would do is call someone "reputable" like Race Tech , and ask them how much to Remove the bad Lug , and Replace it with a "used" one (they should have some laying around) , if the Rebound Rod is scratched up , then you should replace it as well at the same time , you will NOT have to replace the entire inner cartridge , just the rod itself , and it can be used as well , as long as its not scratched , again , Race Tech can do this as well , or you can do it , i can walk you thru removing and swapping parts if you like , its not that hard to do , just a few tricks to keep from damaging the Cartridge Seal when removing and reinstalling
I feel bad for you , a friend of mine had his suspension on his 02 KTM 520XC done in a "shady" shop and they destroyed his just like yours is , and they put it back together and never told him they ruined it , i walked him thru replacing it , and he is good to go (hhis WP fork does not screw into the Lug like Showa does , it screws into the cartridge itself and is held in place by the pressure of the spring along with a O-Ring , but the nut itself was destroyed to the point when he went to change oil , the Adjuster pulled right thru into the inside of the fork , he was pissed .....
I know the initial damage was your mistake , but that does not mean a shop should take advantage of your delima and do shoddy work .... , hopefully it gets you thru the riding season without leaking , then you will have time to either find another fork lower leg (you find them from time to time on ebay , a 05-08 450R or a 04-12 250R or 05-current 250X should fit as well along with 05-current 450X) , if its a complete fork , then the R's will have stiffer outer tubes (the gold larger tube) but the rest should interchange and then just swap to your springs and Cartridge for the matching valving and you will be good to go ....... or get yours repaired as i mentioned