Lack of proper training for engineers & too-harsh targets for sales. I survived in the job simply because I was prepared to put in so many unpaid hours outside the 9 to 5, I just found it interesting. I found there was a real cameraderie amongst telecom engineers both onsite and online and that helped immensely in both tangible and intangible ways. No family to look after at the time so it didnt matter me spending unlimited time training myself.
A lot of the guys I worked with ended up having big arguments with management because they (quite rightly really) weren't prepared to spend endless hours winkling out programming manuals & advice from the internet in their own time, and demanded to be sent on the proper manufacturer training courses, at huge expense to the company.
When management refused, the sales teams ploughed on regardless of whether the engineers had been trained, had trained themselves, or were simply clueless.
End result, chaos..