MTNL Mumbai card in BSNL Sangli-Miraj Area giving horrible speeds


MTNL Mumbai
I am MTNL Mumbai user currently in BSNL Miraj area in roaming.Since last 4-5 days I have been experiencing extreme speed fluctuations in download & upload speeds.
The speed at one time reaches as high as 6Mbps and then within few seconds comes to 0.0Kbps .And this occurs all the time,maybe a little less in the night coz my downloads get completed by morning
Also for 2-3 hours there was no network at all (not continuously but summating the entire duration).I called up MTNL Mumbai they said they have called BSNL Sangli regarding this problem and that their guys would come after prior intimation to do a site inspection.However no one has called from BSNL Sangli as of yet.My signal range is good with all signal bars
All was well prior to 3 Feb 2015.Is any on else facing the same problem ? Is BSNL trying to throttle/shape my btraffic since I am not their customer technically speaking ? I would be glad if some experienced people give suggestions on solving the problem.Also other people from Sangli Miraj area post here if you are facing the similar problems.