Agarwal Packers & Movers — Is this Extortion by Agarwal Packers and Movers?

On 14 June, I contacted Ms Agarwal Packers and Movers (APML) for transporting my household goods from Bengaluru to Panvel, Navi Mumbai. A quotation for Rs.43147/- was sent to me on the letterhead of DRS Dilip Roadlines Ltd ( Brand of Agarwal Packers and Movers) by Nandini on behalf of Agarwal Movers and Packers. One Nandini Nadar, claiming to be an employee of M/s Agarwal Packers and Movers, got in touch with me on WhatsApp ( Mob. No. [protected] carrying APML Logo, Location at New Delhi) and negotiated the deal for the goods as per list excluding car, at Rs.27748/- including taxes. The deal was agreed to and the movement done vide GC No. 4812962 dt.[protected] on the letter heads of DRS Dilip Roadlines Ltd – Brand of Agarwal Packers and Movers
Three days after taking possession of my goods, I was asked by the same mobile ( sometimes a female voice, sometimes a male voice) to pay an extra amount of Rs.5000/-. as they feel that the number of packages is more than what they had envisaged, even though the items were same as per the list on which our agreement was made. It may be noted that each chair, jhadu, etc is counted separately. (Wonder why they did not count each tooth brush also as separate item). Many things had no packing done and only a piece of paper was wrapped around them for writing number on them.

To get back my goods, I paid the full amount by net banking, including the extra amount to the account provided by them i.e. Via account payment: Bank Name:- ICICI BANK,
A/C Holder Name:- DRS DILIP ROADLINES LTD, A/C NO. –[protected], Branch Name:- MG Road Secunderabad, IFCS Code:- ICIC0001121, Regards, Nandini Nadar, Senior Coordinator – Relocation.
After having entered into a contract, and having taken possession of my goods, can they revise charges? Had I known the revised charges before hand, I would not have entered into an agreement with them.
I was threatened that if I do not pay, the goods would be confiscated at their godown.
Does it not amount to extortion, or may be even blackmailing a person aged 76?
To get possession of my goods I was forced to make the payment as told by Ms Nanadini Nadar.
When I wrote to APML about the extortion, they say the consignment case does not belong to them. Then I mailed the complaint to Ms DRS Dilip Roadlines Ltd, but they did not responding to my correspondence.
I am confused. Who has transported my goods Ms Agarwal Packers and Movers or DRS Dilip Roadlines Ltd? The persons who came to collect goods wore shirts with large logos of APMK. The boxes in which the goods were packed carried logo of APML all round. The vehicle on which the goods were loaded had a large poster painted of APML on its side. Now how can they wash their hand off the deal?
The photograps of the quotation, the whatsapp chat with Nandini in pdf, GC No. 4812962 dt.[protected], , the list of packages, photos of the persons who came to collect goods, the vehicle, Mobile Info of Ms Nanadini are all attached herewith.
But I feel this is the most unethical and perhaps illegal act on the part of DRS Dilip Roadlines Ltd. / Ms Agarwal Packers and Movers.
Kindly look into the matter and get me the refund of the extortion amount of the charges.
Thanking you.
Narender Kumar.