Validity of unsigned document

Sir, The head of office has relieved me from office on the basis of an unsigned document issued from the higher office having 3 pages and copy of the unsigned document has been given to me along with the relieving order.In the relieving order the number and date of the unsigned document is shown as Order Number dtd. so and so. But when the same was published without any changes in number, date and contents and with signature of the Section officer of the higher office, the document is having 2 pages only. Can I challenge the document legally? The head office has stated that the higher officers has informed that there is Supreme court order stating that only knowledge of an order even without signature is sufficient to relieve an employee from an office and it is not necessary that copy of the order should be given to the employee along with the relieving order. Kindly provide your valuable advices and if possible the Supreme court judgment so that I can challenge the said action. With regards, Rajasekharan V M