HELP !ECM PCM REPLACEMENT
 

I purchased a used oem pcm ecm module from a reliable source brought it to the dealership along with new batterys prior to finding out my module was fried i had them rewire my whole truck i also have a gt bully dog tuner installed long story short the dealership has not been keeping me i. Touch updated or return calls theyve had my vehicle for months telling me there working on it or there techs quit.. So they finally installed it and say it starts when it wants to will run and dosent stay running . they are saying i need to.pay 3000 for a new computer including install they were telling me from the beginning that its not gonna work and ive had prior experinces with being cheated and have a strong feeling they just didnt program it or troubleshooted sensors i also habe a viper alarm and remote start i read this could also be an issue. But it starts and runs. Should i buy a new one or take it somewhere else ?