1999 GMC Suburban What should I do?

After replacing the lifters I drove my 9th generation K2500 Suburban into a local shop for a timing check(it was running fine). After a day and a half I received a call from the mngr saying I need to come listen to the motor, its rattling like crazy. Now, I used to own my own auto repair business in 1990-93 so replacing lifters is simple, especially in the 454 vortec. So when I get to the shop the mngr attempted several times to start the motor and it sounded as if the timing was WAYYY off. Finally, he managed to get it started and it sounded as if the wires were all crossed and it also developed another knock. So he called the mechanic over that did the work and he said it was -5BTDC. I know this is not too bad, then he stated he corrected it to "0". He even confirmed the vehicle drove into the bay just fine. I have a feeling my engine was sabotaged to get me to spend $$$ at their shop. The mgr was asking question like "did I remove the timing chain"? If these guys new what they were working with, there is NO timing chain, its geared! It sounded like he was trying to say I messed up the installation of the $200 set of roller lifters my son and I installed. The reason we installed new lifters, is it started knocking. This particular motor(is well known)from the factory for inferior lifters. Its all over internet forums. The motor ran less than an hour with the knock and was tore down, finding the bad lifter and replacing it along with the rest. The engine ran great after we got done with NO knocking. Now, I believe this type of lifter requires 1000 mile break in period? The short of it, I took my good running car into this local shop and now it knocks and runs worse than before any work was ever done. It wont even drive out of the shop! What should I do? Have them fix it, have it towed to my home or taken to another shop? Who picks up the cost of this catastrophe? I need a second opinion.

Thanx
William