Who told you that wallet address change after each time you receive bitcoin? which wallet are you using?
Bitcoin wallet address once generated stays there and you can receive as much bitcoin as you can to this address and for how long you want.

you are not saying which wallet you are using, it is different for each one of them!
and in case the wallet is designed correctly, it should keep all the previous addresses in your wallet file in order for you to be able to access the funds later if they received anything.

in any case you have to tell us the name of the wallet and ask your question in its board.

edit: i see you said blockchain while i was typing, in case you mean blockchain.info wallet they yes it keeps all your addresses and you  can use them later.

To add to the answers so far. There is no limit to your address. you can have all the Bitcoins in one address and you can make unlimited transactions with one address. Also you can have an unlimited number of addresses. Here is what you should consider. To many addresses can be inconvenient to keep track of or/and in order. Using an address more then once is just the same regarding safety as using a different one every time, but you can improve your anonymity using a new one for very transaction.
If you receive a payment on your old and once used address, then you still have access to the founds, of course you should still have the private key to it.

don't worry,you will get your coins no problem
blockchain.info wallet changes the recievieng address for increased privacy and security of your coins
all of the addresses it shows you are valid to recieve coins at,same goes with XAPO online wallet and many others

I guess you're using Blockchain.info - that website has this feature turned on so that you get a new address every payment in order to ensure your anonymity. I am using Blockchain too and I have seen that too, but you have to choose there between your wallet and a new address.

in order to make sure, sign in your wallet account at blockchain.info and then from the left panel choose your settings and go to your wallet section (i think it is called wallets) and inside that section you can see your wallet name (which you can create multiple of) and if you click in you can see all your addresses.

also when you signed up they gave you a seed which you can use to recover all your private keys with it.

There are many kinds of receiving address, they have multiple address or single address. Multiple address is when you received a money, the old wallet address will replace by new wallet address. And in the single address is when you used it, it will never be replace by another address, it is also called permanent address.

though address changes after each received Bitcoin, but you can still use the old address for the next payment, no need to change the address

Its seems like natural issue that almost people facing this specially blockchain,coinbase such of online wallet.Once our bitcoin address receives an incoming payment there a new address will automatically be generated for you after every transactions are made,that is normal.Need not confused that,i ensure you its safe to re-use to your last generated payment address.

when it comes to matters of technical aspect please don't assume things and don't say what you "think" if you are not familiar with what is happening. right now you are giving false information.

the only reason why some wallets are generating new address for new transaction is to prevent address reuse which is a recommended technique from day one read about it here: https://en.bitcoin.it/wiki/Address_reuse