That tech is a most likely a liar, and possibly a moron. You have major issues on your line. Your entire upper frequency downstream block is completely missing. Your link is dropping as a result of signal loss and the gateway has a very hard to retraining once it drops. You also shouldn't have a corrected block rate nearly that high. Put in a call to Tier 2 or post in the ATT Direct forum and see if they can get someone out there who isn't an idiot to fix your line.