Do I have to pay back relocation allowance?

As mentioned in my offer letter, relocation can only be recovered in case of resignation within one year from the date of joining. I have already completed around 20 months and hence this deduction is not applicable to me.But company is asking to return the same stating the reason that The policy on Relocation Assistance clearly states that ‘the relocation expenses that are reimbursed and the amount spent on accommodation is recovered in full,if the employee decides to leave the Company before one year from the date of payment’. Additionally,the Employment Agreement that governed your employment with Arcesium also provides and states that ‘The Employee agrees to abide by all policies,rules,and guidelines generally applicable to other employees of the Company. The Company’s policies,rules and guidelines may be amended from time to time and shall be treated as incorporated in this Agreement’ and current policy of the company will supersede the provisions of the Offer Letter.What to do?