I was reading an article a few weeks ago (I cannot find it any more) from Business Insider about a Malaysian telco's experience with Huawei.
NOTE: Huawei has a strange management structure -- Rotating CEO position.
So it starts with the requirement to do a major upgrade (from 3G to 4G or something).
So with the contenders lined up, the Malaysian telco took a leap and went with Huawei (due to price difference). After the contracts were signed, Huawei pulled all the stops. Everything. Huawei wants everything to go as painless as possible and a lot of things done that was not agreed and not in the contract.
Next, in one particular segment of the migration things hit a major impasse between the telco and the Huawei engineers onsite (yes, Huawei sent their engineers to Malaysia to help instead of doing things remotely) . The Malaysian telco CEO wasn't pleased. So he placed a call to the Huawei's Rotating CEO for an informal phone "chat".
Within a week, all of the Huawei engineers were replaced and the works progressed.