Help required to replace lawyer with on going cases

Hi Kanoon, I am writing on behalf of my mother, who has been the plaintiff for a family partition case since 2006. We had appointed a local lawyer and he had given vakalat first the two cases. First case is a family partition case between my mother (plaintiff) and her brother (defendent). This case have been disposed with the Sr principle civil judge delivered the judgement and the defendant has appealed in High court of AP. This is still going on in High Court of AP. Second case is a share of compensation that my mother (plaintiff) is seeking from the defendant who received as a compensation when defendant received when Govt of AP has acquired the land that was part of dispute. The principle amount is approx Rs 165000.00. This case is still proceeding at the lower court. Initially in 2006, when we filed these cases through my mother lawyer, the lawyer was a friend of my family friends. Through my family friends we have approached him and requested him to take up these cases. We have never discussed about his fees nor any payment schedule with him nor he has mentioned in the beginning. But during the course of these cases, we have been paying on regular basis is for various purposes to him.For which we have not received any receipts from lawyer. We almost paid Rs 100000.00 till now( including court fees). All of these transactions are by cash except Rs 30000, which has been paid via family friends and bank transfer. Now the lawyer is saying to take cases back by paying the dues. He has issued a letter from him saying the same. On 05-Dec-2018, he requested the court also to issue a notice as well asking my mother to join in court but we have not yet received but we came to know about the notice. Now, when we asked him about the dues, he is claiming that he wants a 50% share of land of mother share (30 acres). Also 50% share of the compensation amount for the current case. We can not afford to pay such Hugh amounts that he is asking for. For now he can only settle for 50000 as advanced to proceed with cases. We don’t know what to do and how we can solve this. We are looking for advice and support from Kaanoon to advice on how to proceed. We have hearing on 17-Dec-2018 at local court and my mother will be attending it. Please advice how to proceed further. Regards Jayakrishna T.