Dell should be able to supply you with a Windows 7 Reinstallation DVD/USB; call technical support and try again, the response sometimes differs from person to person and region to region. Where are you located, did you buy the pc direct from Dell? There are unfortunately many customers which experience issues procuring installation media from Dell and I have brought this up multiple times on IdeaStorm. If in the US or CA you can likely also fill in the media request form here:

www.dell.com/recoverymedia/

Unfortunately Dell don't extend the courtesy of the media request to other countries and your only choice to procure media from Dell is by calling technical support.

For this reason I often recommend use of a Windows 7 .iso from Digital River and the Activation Backup and recovery program:

http://dellwindowsreinstallationguide.com/download-microsoft-windows-and-office/download-microsoft-windows/windows-7-sp1-iso-download/

http://dellwindowsreinstallationguide.com/a-clean-install-of-windows/microsoft-product-activation/the-activation-backup-and-recovery-program-windows-7-version/

This gives you a downloadable solution to reinstall Windows 7 with the Dell system locked installation mechanism of the reinstallation DVD. The problem is more present with Windwos 8.1 as Microsoft failed to provide a direct link to a .iso which is probably one of the reasons it is so unpopular.

Regarding Office 2013, a MPI card should have been shipped with the system:

http://dellwindowsreinstallationguide.com/download-microsoft-windows-and-office/download-microsoft-office/microsoft-product-identity-mpi-card/

Dell in general do not preinstall and activate Microsoft Office, so you would have had to done so yourself when you got the system and hence received a MPI card.

I haven't purchased an Office 2013 license however it seems that when you first install it you have to register it with a Microsoft Account, you should be able to retrieve the product key and download Office 2013. See here:

http://office.microsoft.com/en-us/support/how-do-i-recover-or-replace-a-lost-microsoft-office-product-key-HA104172018.aspx

You likely won’t need to recover or replace the product key if you purchased Office 2013 online or it’s been installed once before. To install Office, go to My Account, sign in with the Microsoft account tied to the product and use the Install button on the My Account page.

If you’d prefer to install Office using a disk and you need the product key, you can find it on your My Account page. Under the Account Options, click Install from a disk. On the next screen, click on I have a disk, and then click on the View your product key button to display the install product key.

 Important    If the My Account page indicates Office isn’t associated with this account, it could mean the wrong Microsoft account was used to sign in. You’ll need to sign in with the Microsoft account that was entered when you redeemed and installed Office for the first time. If you continue to have problems signing in to My Account, please contact Microsoft support to review your options.