Sun Devil Auto Falsifying Parts and Work Done on Car Phoenix Arizona

I took my 2003 Saturn Ion to Sun Devil Auto on Ray road off of the 10 freeway on Saturday November 8th,2014. I took my car in to get diagnosed due to the fact that it wasn't running properly and showed signs of misfiring. I payed for the diagnosis and was told that the car needed a new ignition coil, a coil pack, and new spark plugs. When i received this quote i told Dave ,who was helping me ,that i didn't have the money for the repairs at the time and that i would need to come back monday, because i had to be at work on saturday and they are closed on sundays, and either get it towed back home on monday or see what other options i could take in getting it repaired. In the meantime on Sunday i researched how much the coils would cost and found that i was being overcharged upwards of 500. The coil pack online can be found for 80 and the ignition coil can be found for about 80-85 also, they were about to charge me over 500 for those two items alone. Because of the research i performed i called another local mechanic and he stated reasonable prices for parts and labor so i decided i would take the car to him to get fixed. I returned to sun devil auto monday evening and spoke to the manager and stated that i was their to tow my car elsewhere for repairs, he said ok and walked me over to my car. I put the key in and it started rough as it did before and didn't want to shift as lurched it over to the tow truck. I towed it to the other mechanic's place of business and had him fix it. He showed me the parts he was taking off and also what was being replaced and gave me advice on future maintenance. I was pleased and rode home happy. It is now Tuesday morning and i receive a call from Dave at SunDevil Auto once again, Dave states on the phone that when i picked up the car he had put new parts in their to test and that he didn't know i was going to pick it up, i stated that i never authorized, signed off on, gave permission, or was ever alerted at any time that this was to be done, especially since when i turned on the car to get on the tow truck the same problems are occurring. Dave stated that i needed to bring the car back in so he can get the supposed parts off,that nobody knew about, back off. I stated to him that was not going to happen because i had already taken the car elsewhere and it had been fixed. So now after all this has happened he's stating that i need to bring the parts that he states were put in back. This simply cannot happen because i was never informed of this and was never charged for these things and when i went to pick up the car with the tow truck it was still having the same problems. I can't trust that anything SunDevil Auto says and I can't believe anything was put in, and now i'm being harassed to bring back parts that were never authorized or even permitted to be put in at all after i had my car fixed elsewhere. I was never handed a receipt for any separate work or parts and I left freely with manager right there never once saying anything of the supposed parts being put in. This all sounds very fishy on SunDevil Auto's part and I can't trust them on any terms, and I will not accept this unprofessional way of trying to conduct business or the way in which they are trying to swindle me afterwards!