Whirlpool India — inefficient customer service team| no bills given since 1 year for amc

I have taken amc plan from whirlpool company as i have their ro purifier. Payment was made by cheque. Once credited to their account the plan was activated & we received amc successful email & usual letter. To claim in office & for records ; since 2017 ; i am asking them to give me a receipt mentioning the gst number & amount paid but company is unable to provide.
Service renewal agency has no answer as they are saying company has change the format & ask us to approach cal center. Call center says call back will come from local regional agency. But since last august 2017 till date the case is still going on.
As last resort ; i also told them that please issue letter individually to me referring my name, emp number with amc amount in favor of my office mentioning my company gst number so that when i claim that my money from my office as per my eligibility ; my office can claim itc on the bill submitted by employee. Complete format has been shared but still no response.
Water purifier - water-ro chassis no. Cnt[protected], purchased on 30 aug, 2017. Existing amc plan purchased /assuredge plan starts on 30 aug, 2017 and expires on 29aug, 2018.
Ro registration plan application number - hp17809348 ro plan taken - an ro-2012-comprehensive-plan-dlx-elt-12m plan code no. 1023706.

Solution need :
1. Company should provide proper bill with amount & their gst number mentioned.
2. As a working class and my designation we receive option to reimburse ro maintenance plan cost from office ; so whirlpool company should provide bill to consumer as per official format certified with my company gst number. There is complete thread of email with them but no response from company towards solution