Working with offshore industry partners

I work for a telecommunications business and about a year ago we moved most of the back office type work offshore, including some customer contact functions associated with this work. Command and control of the functions was to remain onshore, while the work was performed in India.  

A number of my team and I work with them during the start-up period, training staff to help them to learn our processes and become familiar with the western culture.  We seemed to have built a good working relationship from the chaos with which we started.  Since the team returned home, the working relationship has deteriorated with increasing lack of response to our requests for urgent actions to be done and increasing escalations to the offshore management team. 

Obviously we are becoming increasingly frustrated with this situation due to the additional time we have to spend on continual tracking and following up just to get the bare minimum done.  There appears to be a cultural gulf between the business norms on and offshore, with a lower level of responsiveness to our female SMEs than to the males; deadlines on report completions continually being extended; lack of quality in the work completed; lack of openness around what challenges are being faced and what concrete actionable plans are in place to address the issues; regular failure to attend planned meetings....(sorry if this sounds like a bitch session).  Along with these issues is the poor quality and quantity of their work output leading to work backlog and increased customer complaints.  My managers are aware of the situation and advise that they are speaking to management of the offshore industry partners but the situation continues. 

If you have experience, suggestions or success in working in this sort of situation, I would really appreciate some ideas on how to move forward as I am almost at the stage where I want to move away from work I love because of the ongoing stress of having to deal with the same stuff day after day with no progress.